426 



THE POPULAR SCIENCE MONTHLY. 



oils by the process of absorption, and of es- 

 sences and essential oils by distillation. To 

 make pomade, a square frame or chassis of 

 white wood, about twenty by thirty inches, 

 is set with a pane of strong plate glass. On 

 either side of the glass is spread a thin, even 

 layer of purified and refined grease. These 

 frames are prepared beforehand, and kept 

 for the time of the flowers. This having 

 arrived, the petals are picked from the blos- 

 Boms and laid so as to cover the grease in 

 each frame. These are piled one upon an- 

 other so as to fit closely together, when there 

 is formed a kind of tight chamber, the 

 floors and ceilings of which are of grease 

 exposed to the perfume of the flower-petals 

 within. The grease absorbs the perfume, 

 while the spent flowers are removed daily 

 and fresh ones supplied for two, four, or five 

 months, according to the strength of per- 

 fume desired in the pomade. The perfume 

 may afterward be extracted from the po- 

 made by alcohol, when it becomes a floral 

 water or extract. Coarser pomades are 

 made by boiling the flowers in the grease, 

 and subjecting the residue to pressure. The 

 spent pomades are used for toilet purposes, 

 and in the manufacture of fine soaps. When 

 perfumed oils are wanted, superfine olive- 

 oil is used, and cotton cloths saturated with 

 it take the place in the chassis piles of the 

 grease coating on the glass. Essences and 

 Bcents are produced by ordinary distillation. 



The Best Asphalt. — No artificial mixture 

 of bitumen and calcareous matter, says Mr. 

 W. Y. Dent, in a lecture before the Society 

 of Arts, is so well adapted for the descrip- 

 tion of asphalt used for road-making pur- 

 poses as the natural deposits found at Val 

 de Travers and at Seyssel. Its superiority 

 is possibly due to the perfect manner in 

 which, by the enormous pressure to which 

 the deposits have been subjected, the in- 

 gredients of the rock have been incorpo- 

 rated. The native asphalt rock consists for 

 the most part of carbonate of lime, more or 

 less impregnated with bitumen, the quantity 

 of which varies from about six to twelve per 

 cent, that from the Val de Travers, in the 

 canton of Neufchatel, containing rather more 

 bitumen than that of the Seyssel. The pre- 

 pared asphalt, as sold by the makers under 

 the name of " mastic," is made by crushing 



the asphalt rock under a steam-hammer and 

 grinding it to powder by edge-runners. The 

 powdered rock is then carried forward by 

 means of an endless screw to cast-iron ves- 

 sels placed over a fire, in which it is mixed 

 with suitable proportions of fine sand and 

 bitumen and kept constantly stirred for two 

 or three hours, when it is run into blocks 

 weighing about one hundred and twenty 

 pounds. When the mastic is used it is re- 

 heated with more bitumen, and coarse sand 

 is added to it in quantities, according to the 

 purpose to which it is to be applied. Coal- 

 tar pitch is not an entirely satisfactory sub- 

 stitute for bitumen in this mastic, because 

 when hard it is too brittle, and when warm 

 is too soft and sticky. 



Geography and its Related Sciences. — 



Mr. H. J. Mackinder would define geography 

 as the science whose main function is to 

 trace the interaction of man in society, and 

 so much of his environment as varies locally. 

 According to Mr. Bryce, the environment 

 comprises the influences due to the configu- 

 ration of the earth's surface ; those belong- 

 ing to meteorology and climate ; and the 

 products which a country offers to human 

 industry. The first of these categories de- 

 pends more largely than has been acknowl- 

 edged on geology, and is related to physiog- 

 raphy, which asks, " Why is it ? " to topog- 

 raphy, which asks, " Where is it ? " to phys- 

 ical geography, " Why is it there ? " and to 

 political geography, " How does it act on 

 man in society, and how does he react on 

 it ? " and itself asks, " What riddle of the 

 past does it help to solve ? " We may stop 

 short at any of these questions, but can 

 hardly answer a later one with advantage 

 unless those which preceded it have been 

 answered. Of meteorology, average or recur- 

 rent climatic conditions alone — not weather- 

 forecasting — come within the geographer's 

 ken. In considering the productions of a 

 region, the distribution of minerals is inci- 

 dental to the rock structure. The distribu- 

 tion of animals and plants is pertinent in so 

 far as those organisms form an appreciable 

 factor in man's environment, and in so far 

 as it gives evidence of geographical changes, 

 such as the separation of islands from con- 

 tinents and the retirement of the snow-line. 

 But the study of the distribution of animals 



